Along with the development of a wireless communication technology, the base stations in a cellular network gradually develop towards the direction of miniaturization, low power consumption and low cost. For example, recently invented micro-base stations, such as a Home Base Station (Home NodeB) and a Micro-Base Stations (Pico NodeB) are the representatives in this aspect. In the cellular network, indoor coverage is provided mainly by numerous plug-and-play micro-base station apparatuses and serves as the supplementation of normal macro-cell coverage; in the other aspect, from the perspective of users, the appearance of micro-base stations provides preferential high-speed wireless access services for a user, and it is very convenient and affordable.
Like a normal macro-base station, the micro-base stations are divided into TDD micro-base stations and Frequency Division Duplex (FDD) micro-base stations according to different wireless duplex implementation ways.
A TDD wireless network has a strict requirement on time synchronization among base stations. Therefore, normal TDD macro-base stations are usually installed with synchronization devices, such as Global Positioning System (GPS) or Big Dipper or the like to ensure mutual high-precision synchronization. Considering the cost of micro-base stations, synchronization devices are less likely to be installed, and crystal oscillators of the micro-base stations are generally low-cost products, which will generate great error after used for a period of time. Consequentially, high-precision synchronization between a micro-base station and a macro-base station and between micro-base stations cannot be guaranteed in a current practical application, which no doubt results in a great distance from the synchronization requirement of the TDD wireless network. What is more, since serious interference will be generated when signals are transmitted among asynchronous base stations, a receiving apparatus cannot identify correct signals and the system performance is lowered seriously.